浅水三角洲前缘砂体沉积及渗流特征精细表征——以松辽盆地大庆长垣杏树岗油田为例

Characterization of sedimentary and flow characteristics of shallow water delta front sand bodies: Xingshugang Oil Field, Daqing placanticline, Songliao Basin

针对目前相渗研究与砂体沉积特征结合程度较低的问题,综合利用连续取心井的岩心、测井资料、油藏条件下的相渗测试数据、粒度分析、扫描电镜以及压汞数据,对松辽盆地大庆长垣浅水三角洲前缘亚相中分流河道微相及席状砂微相的沉积及渗流特征进行研究,分析了油水两相流的相对渗透率在分流河道垂向上的变化,以及在席状砂外缘、中部和内缘位置的差异。控制分流河道砂体和席状砂开发程度的因素分别为垂向上的水油流度差异和平面渗流能力的非均质性。浅水三角洲分流河道主体垂向上的相渗形态变化不大,但水油流度差异使底部更易水淹,是造成井间剩余油形成的主要因素;席状砂沉积特征的平面差异使注入水更易沿外缘推进,是造成内缘及中部的储量动用程度低的主要因素。

The low degree of integration between relative permeability research and the sedimentary characteristics of sand bodies was studied.The sedimentary and flow characteristics of distributary channel microfacies and sheet sand microfacies in shallow water delta front subfacies in the Daqing placanticline of the Songliao Basin were characterized by using core and logging data of continuously cored wells,relative permeability test data,grain size analysis,scanning electron microscopy and mercury injection data under reservoir conditions.The vertical variation of distributary channels and the difference of the positions of the outer edge,middle and inner edge of sheet sand were analyzed.The factors controlling the development degree of distributary channel sand body and sheet sand are the difference of vertical oil-water fluidity and the heterogeneity of horizontal flow capacity,respectively.In the distributary channel microfacies of shallow water delta,the relative permeability varies little;however,the vertical oil-water fluidity makes the bottom more prone to flooding,which is the main factor causing the formation of residual oil between wells.The planar difference of sheet sand sedimentary characteristics makes it easier for the injected water to advance along the outer edge,which is the main factor causing the low recovery of the reserves in the inner edge and the middle.